Wand lock for vacuum cleaner

ABSTRACT

A locking mechanism for coupling together tubular sections forming a so-called wand useful in connection with vacuum cleaners and the like. The locking mechanism provides long life in effectively holding together the wand sections, is easy to manipulate and prevents leakage of air from the system.

United States Patent [72] Inventor Carl E. Meyerhoefer Little Neck, N.Y. [2 I] App]. No. 1,387 [22] Filed Jan. 8, 1970 [45] Patented Jan. 11, 1972 [73] Assignee The General Signal Corporation New York, N.Y.

[54] WAND LOCK FOR VACUUM CLEANER 4 Claims, 6 Drawing Figs.

[52] US. Cl 285/7, 285/3l2, 285/332 [51] Int. Cl Fl6l 37/18 [50] Field of Search 285/320, 319, 7, 312, 309, 310, 31 l, 308

[56] References Cited UNITED STATES PATENTS 1,086,312 2/1914 Blaha 285/320 2,53l,525 ll/l950 Oakes 285/3l2 X 2,793,055 5/l957 Meyerhoefer 285/7 FOREIGN PATENTS 391,387 9/1965 Switzerland 285/312 Primary Examiner-Thomas F. Callaghan AltomeysRobert S. Dunham, P. E. Henninger, Lester W.

Clark, Thomas F. Moran, Gerald W. Griffin, Howard J. Churchill, R. Bradlee Boal, Christopher C. Dunham and John F. Ohlandt, .lr.

PATENTEU JANI I I972 3,833; 942

Arrow/5y ywfzz/ WAND LOCK FOR VACUUM CLEANER BACKGROUND, OBJECTS AND SUMMARY OF THE INVENTION This invention relates to an improved coupling intended for use in a vacuum cleaner assembly, and specifically, to a locking mechanism associated with the telescopic coupling of the wand sections forming a necessary part of such assembly.

It has been a longstanding problem in connection with the assembly of vacuum cleaners to provide an inexpensive coupling arrangement such that the tubular sections of the wand, which is used to conduct dirt from the cleaner nozzle, may be easily and quickly connected and separated. Moreover the effectiveness of the coupling must not be impaired by the repeated connection and disconnection of the sections. The firmness of the coupling must be retained over the useful life of the cleaner. It is also a requisite that only insubstantial air leakage be permitted by the coupling arrangement.

For an appreciation of the essential problem and of one answer thereto, reference may be made to US. Pat. No. 2,793,055 which describes a telescopic coupling arrangement of wand sections and which involves a cam latch means. Despite the effectiveness of that coupling arrangement, it necessitates a closely fitted leakage prevention means in the form of a rubber sleeve or similar device so that the wand sections are completely sealed. The great advantage of that coupling arrangement, however, is that it affords minimal wear on the wand sections because the cam which is provided bears against a special strip made of hard metal such as steel. As is well known, the tubular sections forming the wand are thin walled and are ordinarily made of a metal which is not especially hart. As a consequence, if the cam were so disposed as to be repeatedly brought into engagement with a wand section, it would indent the same such that the coupling would become less firm after continued use. Thus an initially tight coupling could not be maintained over a long period.

Accordingly it is a primary object of the present invention to insure the effectiveness in the telescopic coupling of wand sections by maintaining substantially the same force in achieving the coupling regardless of wear.

Another object is to minimize air leakage by the very same means which achieves the above-recited object.

Another object is to provide a simplified structure having a minimum number of components and therefore being inexpensive to produce.

A further object is to provide parts which are adaptable to dimensional variation in the manufacture thereof.

The above objects are fulfilled by the wand-locking mechanism of the present invention according to which a cam element is provided and is operatively related to a clamping band which circumferentially surrounds a wand section. A portion of the clamping band constitutes a bearing surface for the cam element, thus realizing the objective of minimal wear of parts. Moreover, and most importantly, the band is con structed of spring material and is so related to the cam element that the force applied as the cam is brought down against the bearing surface, operates to tighten the band and thus compress the outer wand section of the telescopic pair. The force applied is effective due to the fact-that the cam element is mounted for rotation between oppositely disposed-projections, one of which is adjacent one end of the band and the other of which is located at the other end of the band.

The above and related objects, features and advantages of the present invention will become apparent by reference to the detailed description in connection with the drawing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a plan view of a coupling arrangement, illustrating the locking mechanism of the present invention.

FIG. 2 is a sectional side view thereof.

FIG. 3 is a transverse sectional view taken along the line 3- 3 as indicated in FIG. 2.

FIG. 4 is a fragmentary transverse sectional view similar to FIG. 3 but showing the cam element in the release position.

FIG. 5 is a plan view showing a portion of the outermost wand section previously illustrated in FIG. I, with the clamping band and cam element removed therefrom.

FIG. 6 is an exploded view of the clamping band and cam element of the locking mechanism of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawing and primarily to FIG. I, there is indicated a pair of wand sections 10 and 12 in conventional telescopic relationship, according to which the outermost section 10 has a suitably flared portion and the mating section 12 has a tapered portion. A- slot 14 is provided in the outermost section 10 and extends axially through the wall thereof from the telescoped end. The slot has a portion 14a of enlarged width for purposes which will become apparent.

The clamping band 16 circumferentially surrounds the section 10 adjacent the one end in question. One end of the band terminates in an ear or outward projection 18. The other end of the band 16 terminates in a portion 20 serving as a bearing surface for a cam element 22 which is pivotally mounted by means of the pin 24 extending from the aforesaid projection 18 to an oppositely disposed projection 26 which is formed as part of the clamping band 16 adjacent the end thereof constituting the bearing surface 20.

A handle or actuating portion 28 is provided for the cam element and is preferably U-shaped in cross section. As will be seen in FIG. 3 when the handle is brought down suchthat the cam element bears against the portion 20, forces applied by the cam element are effective, due to the face that the cam element is connected to the opposite end of the band, to tighten the band and thus to compress the outer section 10. When the handle is raised the forces are no longer applied and the innermost section 12 can be withdrawn.

It should be noted that the clamping band is not free to move around the outermost section since its bearing surface 20 which overlies the enlarged portion 14a of the slot, is provided with inwardly projecting ears 29 that will engage the sides ofthe opening should there be any tendency for the band to slip. However, the ears 29 do not extend transversely so far as to interfere with the desiredcompression of the outermost section.

Special note should be taken of the fact that the clamping band 16, which is manufactured of spring material, is configured at its portion 30, opposite the bearing surface 20, to have a slightly reverse curvature and is provided with a slot 30 so as to permit ready flexing in this region. The general configuration has been so chosen that significant variations in sizes of wand sections can be tolerated without substantially affecting the desired tightness of the lock. In other words, the tightness can remain substantially uniform'from unit to unit.

It will now be appreciated that the objects previously noted have been achieved by the present invention andthat the locking mechanism described-is uniquely adaptedto provide long-lived coupling of wand sections. Of course, it will be understood that the locking mechanism canlikewise 'be applied to tools or accessories forming a part of the vacuum cleaner assembly.

What is claimed is:

1. A locking mechanism comprising in combination:

a pair of tubular sections having ends adapted to be disposed in telescopic relationship, said sections each including walls of a thickness and of material such that they are flexible under pressure, said outermost section having a slotted opening extending axially from its telescoped end;

a clamping band circumferentially surrounding the outermost of said sections adjacent its telescoped end, said band having an integral bearing surface portion overlying said slotted opening; and

a cam element pivotallysupported for rotation between oppositely disposed, outwardly projecting portions of said band and which are located adjacent either end of said band;

3 ,63 3 ,942 3 4 means for rotating said cam element to cause its periphery 3. A mechanism as defined in claim 2, further including a to act against the bearing surface portion of said band so relatively flat slotted portion of said band lying opposite said that said band is tightened and the outermost section is 8 P" compressed. 4. A mechanism as defined in claim 3, in which said means 2 A mechanism as d fi d i claim 1 in which said bearing 5 for rotating said cam element includes'a pivot pin extending surface portion includes inwardly directed projections for betwee" the utward Prolecuons Ofsald bandabutting against the sides of said openings. 

1. A locking mechanism comprising in combination: a pair of tubular sections having ends adapted to be disposed in telescopic relationship, said sections each including walls of a thickness and of material such that they are flexible under pressure, said outermost section having a slotted opening extending axially from its telescoped end; a clamping band circumferentially surrounding the outermost of said sections adjacent its telescoped end, said band having an integral bearing surface portion overlying said slotted opening; and a cam element pivotally supported for rotation between oppositely disposed, outwardly projecting portions of said band and which are located adjacent either end of said band; means for rotating said cam element to cause its periphery to act against the bearing surface portion of said band so that said band is tightened and the outermost section is compressed.
 2. A mechanism as defined in claim 1, in which said bearing surface portion includes inwardly directed projections for abutting against the sides of said openings.
 3. A mechanism as defined in claim 2, further including a relatively flat slotted portion of said band lying opposite said bearing surface portion.
 4. A mechanism as defined in claim 3, in which said means for rotating said cam element includes a pivot pin extending between the outward projections of said band. 